With reduction in size and weight of electronic apparatuses such as mobile telephones, imaging devices mounted in the electronic apparatuses are also required to be reduced in size and weight.
In the imaging devices, a solid-state image sensing device, such as a complementary metal-oxide semiconductor (CMOS) image sensor or a charge coupled device (CCD) image sensor, is adopted as an image sensing device. Further, a so-called chip size package (CSP) structure is adopted for the purpose of size reduction.
FIG. 14 illustrates an example of an imaging device module that includes an imaging device having a CSP structure.
In this imaging device module, an imaging device 90 includes a solid-state image sensing device 91, and a transparent member 93 fixed to an upper surface of the solid-state image sensing device 91 with adhesive 92.
In this configuration, air is contained in a space 94 defined between a light-receiving area 91A of the solid-state image sensing device 91 and the transparent member 93. Electrodes 95 on the upper surface of the solid-state image sensing device 91 are led out via electrodes 96 extending through a semiconductor substrate 91S, wires 97, and convex external connection terminals 98 that constitute the solid-state image sensing device 91.
The imaging device 90 is mounted and connected onto electrodes 111 on a wiring board 110 with the external connection terminals 98 being disposed therebetween. Circuit elements 112, such as a control integrated circuit element, a resistor element, and a capacitative element, are connected to the electrodes 111 with adhesive 113 such as solder.
On the wiring board 110, a lens holder 120 holding a lens is mounted in a manner such that a lens unit 121 is positioned in correspondence with the light-receiving area 91A of the solid-state image sensing device 91.
The lens unit 121 includes lenses 122A and 122B and diaphragms 123A and 123B. The lens holder 120 itself is lightproof.
Such an imaging device module in which a solid-state image sensing device and circuit elements are mounted on one principal surface of a wiring board and are covered with a lens unit is disclosed in, for example, Japanese Laid-Open Patent Publication No. 2003-169235 or Japanese Laid-Open Patent Publication No. 2008-167426.
U.S. Pat. No. 6,492,699 discloses that cutouts are provided in a peripheral edge portion of the principal surface (upper surface) of a transparent member arranged on a solid-state image sensing device.
In the above-described imaging device module, however, the wiring board 110 needs a large area because the imaging device 90 and the circuit elements 112 are arranged side by side on the wiring board 110. Hence, it is difficult to meet the demand to reduce the size of the imaging device module.
In the configuration illustrated in FIG. 14, the wire length between the upper electrodes of the solid-state image sensing device and the circuit elements is sometimes up to about 5 mm.
Such a large wire length increases the wiring resistance and also increases the influence of external noise. It is therefore difficult for the imaging device module to operate stably.
Accordingly, a technique that realizes size reduction of an imaging device without deteriorating electrical characteristics is expected.